When constructing a home or a facility, it is well known to provide access barriers, such as garage doors, which utilize a motorized barrier operator to provide opening and closing movements of the door. Aside from garage doors, the barrier operator may also be coupled with other types of movable access barriers such as gates, windows, retractable overhangs, protective curtains and the like. In order to open and close the access barrier, a barrier operator is configured to receive command input signals from a wired or wireless transmitter. It is also known to provide safety devices that are connected to the barrier operator for the purpose of detecting an obstruction so that the barrier operator may then take corrective action with the motor to avoid entrapment of the obstruction by the access barrier.
As previously mentioned, wireless transmitters are configured to allow users to conveniently actuate the access barrier in a desired direction without getting out of their car. Additionally, such remote devices may also be provided with additional features such as the ability to control multiple doors, lights associated with the doors, and other security features. As is well documented in the art, the remote devices and operators may be provided with encrypted codes that change after every operation cycle so as to make it virtually impossible to “steal” a code and use it at a later time for illegal purposes. An operation cycle may include opening and closing of the access barrier, as well as turning on and off a light that is connected to the barrier operator and so on.
Although remote transmitters and like devices work well, they can be cumbersome and distracting to the driver, as his or her hands are occupied with maintaining a controlled grip over the steering wheel, or gear shift while exiting the garage or driveway. Depending on the radio frequency range of the transmitter, they can close a barrier, such as a garage door, outside the user's line of sight such that if the safety devices on the operator malfunction the user can close the door on a person standing in the doorway. As such, the potential damage resulting from the inadvertent actuation of the remote transmitter while the vehicle is in the path of the access barrier is increased. Furthermore, the switch mechanism and the battery connections of the remote device typically become worn after a period of time and requires replacement. To overcome this disadvantage, various systems for the “hands-free” operation of the remote transmitter have been developed. Such hands-free systems comprise a mobile transmitter that communicates, via various mobile signals, with a base operator that is configured to actuate an access barrier, such as a garage door, between open and closed positions. The mobile transmitter is generally carried by a carrying device, such as a vehicle, and is configured to transmit mobile signals to the base operator so as to move the access barrier between open and closed positions, depending on the relative position of the carrying device to the base operator, as well as other criteria.
Many of the hands-free systems of the prior art utilize a mobile transmitter that is carried by a suitable carrying device, such as a vehicle, which communicates with the barrier operator, through signals periodically sent to the mobile transmitter, such that when no return signal is received, the barrier operator commands the access barrier to close. Unfortunately, such a manner of operation allows the closing of the access barrier to be potentially initiated with the user out of visual range of the barrier, which may result in safety concerns, as the user may be led to believe that the barrier has closed, or become obstructed with a person (child) when in fact an obstruction has caused the door to open and remain open allowing unauthorized access to others.
Alternatively, other hands-free systems may utilize a system of communication, wherein a mobile transmitter repeatedly transmits at least one identification signal for receipt by the barrier operator. Prior art based upon the received identification signal and other input, the barrier operator controls movement of the door or access barrier. One particular type of hands free implementation used to control the barrier operator utilizes a timeout delay function, whereby when the barrier operator has failed to receive a predetermined number of identification signals, the controller sends a close command the access barrier is automatically closed. However, such systems have a tendency to be inaccurate due to the fact that they rely on the detection of a plurality of signals sent by the mobile transmitter in order to ascertain whether the mobile transmitter has moved away from the barrier operator by a sufficient distance to warrant the automatic closure of the access barrier places the user to far away from the line of sight of the barrier. In particular, inaccuracies may arise due to various sources of interference that may corrupt a transmitted signal, including that of electrical noise for example. To overcome such deficiency associated with transmitting and detecting a plurality of signals to detect the position of a mobile transmitter, various attempts have been made to utilize positional indicators to identify the specific position of the carrying device as it moves relative to the barrier operator. Unfortunately, such systems require that the microprocessor or controller that processes the data generated by such devices be configured to perform floating point and/or vector operations upon the data received from such detection systems, which generally translates into a significant amount of processing overhead for the microprocessor or controller being utilized. As such, to achieve such a level of computational performance, a high-performance microprocessor or controller is required, which is generally a source of undesired expense when contemplating the development and manufacture of such a mobile transmitter.
Therefore, there is a need in the art for an operator system that automatically initiates only the closing sequence for an access barrier depending upon the change in angular position of a carrying device without the need of floating point or vector based mathematical operations. In addition, there is a need for an operator system that utilizes a mobile transmitter that includes an angle position detector that is configured to monitor the change in the angular position of a carrying device as it is removed from an enclosure whose access is controlled by the access barrier and closes predictably within the line of sight of the user. Furthermore, there is a need for an operator system that provides a mobile transmitter that includes an activity sensor, such as an accelerometer, so as to automatically close an access barrier when a carrying device has reached a predetermined linear distance from the access barrier. Still yet, there is a need for a hands-free operator system that provides a mobile transmitter that is configured with an accelerometer that is capable of discriminating between unintended movement, such as the accidental movement of the mobile transmitter within a carrying device, and movement resulting from the acceleration of the carrying device, so as to accurately control the movement of the access barrier within the line of sight of the user.